【笔记】uber--子对象访问父对象的方式

function Shape(){}
Shape.prototype.name = 'shape';

Shape.prototype.toString = function(){
　var result = [];
　if (this.constructor.uber) {
　　result[result.length] = this.constructor.uber.toString();
　}
　result[result.length] = this.name;
　return result.join(', ');
};


function TwoDShape(){}

var F = function(){};
F.prototype = Shape.prototype;
TwoDShape.prototype = new F();
TwoDShape.prototype.constructor = TwoDShape;

TwoDShape.uber = Shape.prototype;
TwoDShape.prototype.name = '2d shape';

function Triangle(side,height){
 this.side = side;
 this.height = height;
}
var F = function(){}
F.prototype = TwoDShape.prototype;
Triangle.prototype = new F();
Triangle.prototype.constructor = Triangle;
Triangle.uber = TwoDShape.prototype;
Triangle.prototype.name = 'Triangle';

Triangle.prototype.getArea = function(){
 return this.side*this.height/2;
}

var my = new Triangle(5, 10);
my.toString()